Calorimetric bomb

HMX, the highest density and highest energy soHd explosive produced on a large scale, primarily for military use, exists in four polymorphic forms. The beta form is the least sensitive, most stable, and the type requited for military use. The mole fraction products of detonation of HMX in a calorimetric bomb are 3.68 N2, 3.18 H2, 1.92 CO2, 1.06 CO, 0.97 C, 0.395 NH3, and 0.30 H2. 

Combustion Calorimetric bomb (Berthelot), oxygen flask (Schoniger), Wickbold apparatus, cold plasma incinerator, micro-Dumas combustion (CHN analyser), sulfur-specific analysers (S, C, N, O), pyrochemiluminescence... 

The heat given out in the combustion of propellants is readily measured by exploding them in special calorimetric bombs built to withstand the high pressures produced. The result thus obtained, however, does not necessarily give exactly the heat available under practical circumstances, as in the calorimetric bomb the products are cooled and can undergo reactions which have different equilibria at high and low temperatures. It is, therefore, usual for design purposes to obtain the calorimetric value of a propellant also by calculation. 

A recent brief review showed the working principles of various automatic analyzers6. A modified account of N and O analysis will be presented here. Today there exist in the market instruments that perform organic elemental analyses in a few minutes. The ease and speed of such analyses enable the use of such instruments for routine analysis. Although some operational details vary from model to model and between one manufacturer and another, all these instruments can be considered as exalted versions of the classical Pregl determination of C and H by conversion to CO2 and H2O, together with Dumas method for N by conversion to N2, the calorimetric bomb method for S by conversion to SO2 and SO3 and Schultzes method for O by conversion to CO. This is combined with modern electronic control, effective catalysts and instrumental measuring methods such as IR detectors and GC analyzers. 

Calorimetric Bomb of Bichel (Bichel Pressure Gage). See Bichel Calorimetric Bomb in Vol 2 of Encycl, p Blll-R... 

Addnl Refs A) J. Taylor C.L.R. Hall, PhysChem 51, 593 (1947) (Calorimetric bomb used by Research Dept at Ardeer, Scotland)... 

It is quite possible in the case of TNT that the true detonation reaction is followed, during the cooling of the products, by endothermic reactions among them, which increase the volume of gas found in the calorimetric bomb at the end of the determination. These could be the "soot reactions ... 

Perez-Ara (1945) Determination of Heat of Explosion (Medicion del calor desarrollado en explosion by means of Calorimetric Bombs of Berthelot (p 63), of Sarrau (64), of Noble... 

Taylor (1952), Measurement of Detonation by Dautriche (pp 24-28) and by Rapid-Photography Methods (28-32) Heat of Explosion by Calorimetric Bomb (40-2) Temperature of Explosion (43-7) Power or Strength of High Explosives by Trauzl Lead Block Test, Ballistic Mortar Test and pendulum Test (185-86)... 

Heat of Deflagration. If an explosive, serving as a propellant (such as BkPdr or a smokeless propellant) is initiated by an electric blasting cap, in a calorimetric bomb (similar to that used for determination of heat of combstn) under confinement, but without addition of oxygen, the substance usually behaves as if it were fired in a gun barrel. This is known as "deflagration ... 

If a calorimetric bomb is not available and if the products of explosion are not determined by analysis, the heats of explosion can be approximately estimated from the equation of explosion... 

Parks, JACS 61, 3543(1939) (Heats of combstn 17) R.R. Wenner, "Thermoche-mical Calculations , McGraw-Hill, NY(1941), pp41-6, 48-9, 51-6, 74 109-11 (Heats of formation) 42, 43 46-9 (Heats of combustion) (No heats of explosion or detonation are given) 18) G.B. Kistiakowsky, OSRD Rept 293 1941) (Determination of heats of combustion of expls) 19) E.J. Prosen F.D. Rossini, JResNatIBurStandards 27, 289(1941) (Calorimetric bombs of Prosen Rossini) 20) G.B. Kistiakowsky, OSRD Rept 702(1942) (Heats of combstn and of... 

Another important characteristic of an explosive which might influence its force is the energy, which is defined as the heat (in calories per unit weight) produced on detonation or explosion. It may be either calculated or determined experimentally using a small, thick-walled calorimetric bomb. 

Filled Mixtures of Ammonium Nitrate with Trotyl , VzryvnoeDelo 1966 (60/17), 160-73 (1966) (Russ) CA 67,55796 (1967) [The author compared dry and w-filled mixts of granular Trptyl (TNT) and AN by means of their heats of expin detd using calorimetric bombs, brisance from Trauzl test data, MacKnee ballistic balance values and ballistic plate tests. Evaluated were composites of AN and TNT in 79/21, 50/50 and 30/70 ratios as well as pure granular TNT. It was found that in the dry state the heat of expln is max for the stoichiometric 79/21 mixt. However, as the TNT content increases, the evolved heat decreases to a min for pure TNT. The w-filled mixts exhibit an opposite trend, viz, the heat of expln increases with TNT content, becoming maximized for 70—100%... 

Bichel Calorimetric Bomb is a heavv-walled cylindrical steel bomb with a removable cover used for detn of the amt of heat liberated during an expin (heat of expln). The original bomb had a 30-liter capacity and was intended for use with a lOOg sample. Later models of the bomb were smaller and lOg samples were used... 

Calorific Values, Calorimetric Values and Calorimetric Potentials of Nitrocelluloses and Propellants, Taylor et al (Ref 2,p 580), define the calorific value as the heat evolved (in calories per gram) when a substance is exploded in a special calorimetric bomb capable of withstanding high pressure... 

Muraour et al(Ref 5,p 273) define "potentiel apparent" as the heat of explosion or deflagration, as detd in a calorimetric bomb at const vol either, in vacuum or in inert atmosphere. This differs from chaieur de combustion" (heat of combustion) which is detd in the bomb in the presence or an excess of compressed oxygen. In the opinion of Muraour et al, it is much simpler, less time consuming, and more precise to aet ana use the values of heat of combustion in lieu of calorimetric values... 

Parr calorimetric bombs and calorimeters are very much in use in the US. These bombs are cylindrical in shape and are provided with covers which can be securely closed against leakage. Detailed descriptions of experimental procedures using Parr oxygen bombs and Patr calorimeters... 

D. R.Stull, Anal ChimActa 17, 133(157)(Automatic calorimeter) aa)C.Napoly et al, MP 41, 155-69 (Contribution to the study of operating conditions for detn of calorimetric potential in calorimetric bombs) bb)S.S.Wise, "The Heats of Formation of Some Inorganic Compounds by Fluorine Bomb Calorimetry , Argonne National Laboratory ANL -6472, Jan 1962, Contract W- 31- 109- eng- 38... 

Less dangerous is the method of combustion in a closed bomb (calorimetric bomb) contg a large amt of compressed oxygen, followed by analysis of resulting gas for the amt of COz formed on combustion of C. This method was first proposed by Berthelot (Ref 1) and modified by Hempel (Ref 2). Badoche (Ref 3) and Burlot (Ref 4) investigated the method and found it to be satisfactory... 

The main physicochemical processes in thin-film deposition are chemical reactions in the gas phase and on the film surface and heat-mass transfer processes in the reactor chamber. Laboratory deposition reactors have usually a simple geometry to reduce heat-mass transfer limitations and, hence, to simplify the study of film deposition kinetics and optimize process parameters. In this case, one can use simplified gas-dynamics reactor such as well stirred reactor (WSR), calorimetric bomb reactor (CBR, batch reactor), and plug flow reactor (PFR) models to simulate deposition kinetics and compare theoretical data with experimental results. 

There has been a discussion of some aspects of the history of thermochemistry, considered as a precursor of the development of chemical thermodynamics.109 There is also a study of C. M. Guldberg (1836-1902) and P. Waage s (1833-1900) attempts to formulate an equation for the temperature dependence of the rates of chemical reactions.110 In 1878, Paul Vieille (1854-1934), who did important work in thermochemistry, invented the calorimetric bomb. In 1884, Vieille suggested that this instrument could be used to determine, in a novel and accurate manner, the heats of combustion of carbon and organic compounds.111... 

If a process takes place at constant volume, the corresponding heat quantity is called the change in internal energy, AU. An example of a constant volume process is provided by a combustion calorimetric experiment where the sample is burned in a closed vessel (a calorimetric bomb) charged with pressurized oxygen. The relationship between AH and AU is given by... 

CA2 = nitrocellulose 11-12,5% N for blasting gelatin (french) calcium carbonate 326 331 calcium nitrate 48 327 calcium stearate 327 calculation of explosives and gun powders 315 calorimetric bomb 161 camphor camphre 49 163 298 327 Candelilla wax 163... 

KA-process (RDX-synthesis) 70 Kalisalpeter = Kaliumnitrat 262 Kaliumbitartrat 221 Kaliumchlorat 262 Kaliumsulfat 221 Kaliumperchlorat 263 Kalksalpeter = calcium nitrate 48 kalorimetrische Bombe = calorimetric bomb 161... 

Unlike the heat of explosion, the heat of combustion represents the caloric equivalent of the total combustion energy of the given substance. It is determined in a calorimetric bomb under excess oxygen pressure. The heat of combustion is usually employed to find the heat of formation. 

The experimental determination takes place in a calorimetric bomb. The bomb volume is usually 20 cm3, but can also be 300 cm3. The... 

Very often, also, all the modifications of the system studied are produced inside of the same combustion-chamber or within the same calorimetric bomb during such transformations the volume occupied by the system does not change, so that the second condition is fulfilled. 

But, as was done by Berthelot and Matignon, the two following reactions may be realized in a calorimetric bomb ... 

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